Drive for rotary bodies having large dimensions and great weight



June 2, 1970 s. MATUSCH ET AL 3,515,009

DRIVE FOR ROTARY BODIES HAVING LARGE DIMENSIONS AND GREAT WEIGHT Filed June 24, 1968 2 Sheets-Sheet 1 I Fig.7

0/ O 4 B o 1 6 O 1 O o PAfSSl/RE 0 4 Flu/D SOURCE lnven tors 2 Sheets-Sheet 2 S. MATUSCH ET AL DRIVE FOR ROTARY BODIES HAVING LARGE DIMENSIONS AND GREAT WEIGHT June 2, 1970 Filed June 24, 1968 lnventolzs United States Patent 3,515,009 DRIVE FOR ROTARY BODIES HAVING LARGE DIMENSIONS AND GREAT WEIGHT Siegfried Matusch, Abbensen, near Peine, and Hans- Dieter Backofen andHelmut Schaper, Braunschweig,

Germany, assignors to Braunschweigische Maschinenbauanstalt, Braunschweig, Germany, a corporation of Germany Filed June 24, 1968, Ser. No. 790,890 Claims priority, application Germany, June 24, 1967,

Int. (31. F16l1 41/22 U.S. Cl. 74128 6 Claims ABSTRACT OF THE DISCLOSURE A drive for rotary bodies having large dimensions and great weight, particularly for a diffusion arrangement in the sugar industry, which comprises an immovable frame and a rotary body. At least two pressure fluid motors of substantially equal output are distributed over the periphery of the rotary body. The latter has a drive wheel at its end face. The pressure fluid motors are operatively connected with the drive wheel. A joint pressure fluid source feeds the pressure fluid motors. The latter comprise at least two pairs of slide piston motors operating alternately, working at equal phases and engaging on diametrically opposite points of the drive wheel, as well as performing overlapping, periodically controllable working strokes. The drive Wheel has driver elements distributed over its periphery, and the driver elements are formed as driver crosses rotatable about axes parallel to the rotary axis of the drive wheel and automatically arrestable in predetermined positions.

The present invention relates to a drive for rotary bodies having large dimensions and great weight, in general, and to such drive which is required, for instance, for diffusion-apparatus in the sugar industry, in particular.

In known diffusion arrangements in the sugar industry, the large rotary bodies are equipped with a drive wheel, which is formed as a toothed gear. .At one point of the periphery of the toothed gear, yet preferably on several points of the periphery of the toothed gear, drive pinions are brought into mesh with the toothed gear. For driving the pinions, either electro-motors or hydraulic motors are used. Electro-motors are expensive, as well as difficult to control continuously. Its great disadvantage resides, first of all, in the fact that it is hardly possible to build two or more motors which release at the same number of revolutions the same driving torque. From this result appreciably heavy drawbacks. During use of hydraulic rotary motors, the drawback of unequal output is avoided. Hydraulic motors are, furthermore, also controllable continuously as to their number of revolutions to a great extent. Its drawback resides, however, in the fact that the working speed range is so high, that intermediate drives must be switched between the pinions and the out put shafts of the hydraulic motors. The joint drawback of these drive motors resides in the fact, however, that they are very expensive. At least one such motor must be kept in storage, however, in order to be able to pro vide an exchange in case of damage, and in order to avoid in interruption of the operation of the diffusion arrangements.

The diffusion arrangements in the sugar industry are put to operation at the time of the starting sugar campaign, and must then operate continuously up to the end of the campaign. This means that the rotary bodies must remain in rotation continuously. This assumes that even in case of damage, the possibility must be present 3,515,009 Patented June 2, 1970 "ice to remove driving motors or parts of the drive without interruption of the operation.

It is already known to drive rotary bodies by means of slide piston motors, which can be put into mesh by means of suitable toothing with the rotary body. Yet, the great drawback results thereby that the bearings of the rotary body are highly one-sided loaded. Furthermore, either a very strong wear of the inter-engaging force transmitting elements of the rotary body on the one hand, and of the slide piston motor on the other hand, must be taken in stride, or lifting devices of excessive structure are required. Furthermore, the operation of the diffusion arrangements requires a uniform run of the heavy rotary bodies, andwhich cannot be obtained with the known drives used overwhelmingly for switching purposes with slide piston motors.

It is, therefore, one object of the present invention to provide a drive for a rotary body of enlarged dimensions and great weight, particularly for diffusion arrangements in the sugar industry, which drive can be operated by means of slide piston motors without necessity to dimension excessively the bearings of the rotary bodies.

It is another object of the present invention to provide a drive for a rotary body, having large dimensions and great weight, which aims to design such drive such, that a wear of the force transmitting elements is extensively avoided.

It is still another object of the present invention to provide a drive for rotary bodies, having large dimensions and great weight, wherein a drive for the rotary bodies of the mentioned type is provided in which, by using slide piston motors, a uniform rotary movement can be brought about.

It is yet another object of the present invention to provide a drive for rotary bodies, having large dimensions and great weight, wherein the drive is designed such, that the rotary body can be driven with an endless controllable low speed.

It is also an object of the present invention to provide a drive for rotary bodies, having large dimensions and great weight, particularly for diffusion arrangements in the sugar industry, in which, on an immovable frame at least two pressure fluid motors of equal output, distributed over the periphery of the rotary body, are arranged, which engage an end-side driving gear of the rotary body, and can be fed from a joint pressure fluid source, whereby the invention in this drive is seen in the fact that as pressure fluid motors, at least two pairs' of slide piston motors, alternately operable and working with equal phases, and engaging on diametrically opposite points of the drive wheel, the slide piston motors are equipped with overlapping, periodically controllable working strokes, and wherein the drive wheel has driving elements distributed over its periphery, which are formed as driving crosses, rotatable about axes, disposed parallel to the axis of the drive wheel, and automatically arrestable in predetermined positions.

With these and other objects in view, which willbecome apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

FIG. 1 is an end view of one embodiment of a drive,

designed in accordance with the present invention;

FIG. 2 is an end view of the drive wheel with driving crosses mounted therein; and

FIG. 3 is an axial section through one half of the drive wheel, the section plane extending through the axis of the rotary body, as well as through the axis of the driving cross.

Referring now to the drawings, the drive comprises an immovable frame 3 which surrounds a shaft 1 of a rotary body. In the immovable frame 3 are disposed,

in the disclosed embodiment, four slide piston motors 12 and 13, which are disposed opposite each other in pairs, and are swingably mounted on bearing blocks 4. The slide piston motors 12 and 13 are arranged tangentially to a. drive gear 5, which is rigidly connected with the rotary body (not shown). The drive gear comprises, as can be ascertained from FIGS. 2 and 3, two disc rings a and 5b, which are welded to a central hub 5c in parallel arrangement and at a predetermined distance from each other.

The piston rods 12a and 13a of the slide piston motors have at their ends rollers 30, which are rotatably mounted at such distance, that by means of the rollers 30 the piston rod ends support and roll up, respectively, the piston rod ends on the periphery 5d of the discs 5a and 5b of the drive wheel 5.

The swingable slide piston motors 12 and 13, respectively, are under such pretension that they can be retained in continuous tangential arrangement on this drive wheel 5. This pretension can, depending upon the position of the slide piston motors, be produced by the own weight of the slide piston motor, or by one or a plurality of springs 6.

In the disclosed embodiment, the springs are secured with one of their ends on a tread 1a, which is mounted on the hub 50 of the drive wheel 5, while the other end of the springs engages the axle of the running rollers 30 of the slide piston rods 12a and 13a, respectively.

On a joint pitch line of the drive wheel 5 are rotatably mounted a predetermined plurality of driving crosses equally distributed over the periphery. The driving crosses are designated in their entirety by the numeral 2. In the shown embodiment, on the axis 20, which is arranged parallel to the axle of the drive wheel 5 between the two discs 5a and 5b of the drive wheel, two rotary crosses 2 disposed at some distance from each other are rotatably mounted between the discs as a unit. Each driving cross has four driving arms which are formed hook-like. The drivers have claw sections 2a in which the piston rod ends of the slide piston motors engage, if they exert during the working stroke a torque onto the drive wheel 5. The back side of each claw is curved at 2b. The formation of this curved section is chosen such, in connection with the arrangement of the pitch circle on which the axles 2c of the driving crosses are distributed, that when a driving claw stands in the ready position for cooperation with the end of a piston rod, disposed on the working stroke, that the curved rearward section 2b of the previous driving claw projects over the periphery edge 5d of the discs 5a and 5b, such that the curved section 2b forms a run-up section for the piston rod end, and thereby brings the piston rod end out of contact with the periphery 5d of the discs. By this arrangement, a lifting device is avoided, and simultaneously it is assured that during the working stroke the piston rod is free from the periphery of the discs, so that no bending moments can be introduced into the piston rods.

The driving cross is arrestable, as shown in FIG. 2, in predetermined positions, whereby in these positions always one driving claw is in the ready position. For the arresting serves a ratchet pawl 9, which is swingably mounted between the discs 5a and 5b, on the axle 8, and which can be adjusted exactly by means of a screw in its arresting position. The ratchet 9 is under the effect of a pull spring 11, the other end of which is secured on a bridge between the discs. The arrangement is made such that each driving cross can swing in a rotational direction opposite to that of the drive wheel 5 which is given by the arrow A, and in particular by elastic displacement of the ratchet pawl 9, whereby, however, a return rotation is prevented in each case by the ratchet pawl 9 which finds rigid engagement in the curved section 2b of one of the driving crosses, and

simultaneously serves for the transmission of the torque from the driving cross over the arresting ratchet pawl 9 and the rigidly formed axle 8 to the drive wheel 5.

It has been found very advantageous, if four slide iston motors are provided in pairs, operating in equal phases. Each slide piston motor is operable in both directions, whereby a valve control device (not shown) serves the purpose of periodically reversing the feeding of the slide piston motors. The reversal is released by a sensing device 1212 and 13b, on which the abutment sensors 14 are provided, which determine the two end positions of the piston rod end and, upon reaching these end positions, release the reversal. Suitably, the arrangement is made such that the return stroke of the piston takes place with at least the treble speed of the working stroke.

For a satisfactory working, it has been found particularly suitable that the arrangement is made such that the four pistons reach about simultaneously their center position, whereby two pistons reach this center position on their working stroke, and the other two on their return stroke.

In this position, in a preferred embodiment, the axles 30 for the runners and, thereby, the engaging points of the slide piston motors following each other in peripheral direction, which do not operate at the same phase, are at a relatively angular distance B of about 67.5". It is to be understood that this angle varies likewise with the change in the number of revolutions of the driving crosses. The feeler contacts 14 can be set at both sides such that it is assured at each number of revolutions that this angular distance is maintained. By this arrangement it is assured that the two slide piston pairs overlap each other as an optimum in the working stroke, and, thereby, the highest possible range of number of revolutions is obtained. Thus, in each case, and in particular independently from the chosen number of revolutions, a uniform rotary movement of the drive wheel as assured.

During the fast return stroke, the end of the piston rod of each slide piston motor passes over the driver cross disposed within the path of the return stroke, whereby the driver cross automatically yields by releas ing the arresting pawl, so that a particular lifting device for the piston rod is superfluous. As soon as the piston rod end has passed over the driver cross, the next driver of this cross reaches the ready position by engagement of the arresting pawl. The piston rod can now move during the working stroke into the arresting pawl upon reaching the ready position, and the piston rod can now transmit the torque onto the drive wheel 5 directly by means of the driver cross. Before the piston rod interengages, during the working stroke, the driver claw, the piston rod is lifted by means of a run up cut 2b of the driver cross from the driving wheel, so that any bending moments cannot be exerted upon the piston rod.

For the engagement in the driver claws, as well as for the control of the driver crosses during the return stroke, each piston rod has a cross bolt mounted in the piston rod head, which cross bolt carries at its ends the running rollers 30.

By the formation of the driver cross and the arrangement and distribution of the slide piston motors, a completely pushand hit-free engagement of the piston rod ends is obtained in the driver claws, so that for each drlving arrangement conventionally standardized slide piston motors can be used. These standardized motors are of great price value and rough and lend themselves for use without danger of an appreciable disturbance also In very heavy drives. Its mounting is extremely simple, since they must be suspended merely in the swinging position on the supports 4 and the hose connections are to be provided to the pressure fluid source. The exchange takes place also extremely fast, whereby interruption of the operation of the rotary bodies is not required.

The lifting of the piston rod ends from the drive wheel 5 can be very slow, since the actual Working angle, whichcorresponds with the effective working stroke of the slide piston motors, is relatively small. The lifting can amount to about mm.

The variation in the number of revolutions can be set in a simple manner by changing of the quality output of the pressure fluid source.

By the new arrangement, the necessity of the use of oversized expensive toothed gears for the last step of the drive for transmission of the appreciable torques is avoided. Also, no intermediate arrangement of expensive drives is required, which drives are necessary for obtaining very low numbers of revolutions in known drives. Also, the mounting is appreciably simpler, since no particular attention has to be paid to an expressly exact mounting of the individual drive parts for assuring the required uniform engagements. The new drive can be realized rather with simple, economical and robust structural parts, which lead to a very appreciable saving on costs relative to known drives. The mounting of the slide piston motors is extremely simple, since no particularly great requirements to the individual adjustments have to be made. The engagement and the engagement range of the piston rod ends can be easily and reliably set by the variation of merely the feelers 14 to the desired value. Also, the supervision of the operation is, in the new drive, extremely simple, and repairs can be performed, as already mentioned above, fast and without time loss. In view of the low-priced structural parts, the spare part storage is also extremely simple and economical.

We claim:

1. A drive for rotary bodies having large dimensions and great weight, particularly for a diffusion arrangement in the sugar industry, comprising an immovable frame,

a rotary body,

at least two pressure fluid motors of substantially equal output distributed over the periphery of said rotary body,

said rotary body having a drive wheel at its end face,

said pressure fluid motors being operatively connected with said drive wheel,

a joint pressure fluid source feeding said pressure fluid motors,

said pressure fluid motors comprising at least two pairs of slide piston motors operating alternately, working at equal phases and engaging on diametrically opposite points of said drive wheel, as well as performing overlapping, periodically controllable working strokes,

said drive wheel having driver elements distributed over its periphery, said driver elements being formed as driver crosses rotatable about axles mounted on, and parallel to the rotary axis of said drive wheel and automatically arrestable in predetermined positions and engageable in the latter positions by said slide piston motors for rotating said drive wheel.

2. The drive, as set forth in claim 1, wherein said motors include piston rods, and the ends of said piston rods of said slide piston motors adjacent in peripheral direction and working out of phase reach the stroke center position simultaneously and have in said stroke center position always a shortest peripheral distance of about 67.5.

3. The drive, as set forth in claim 1, wherein said drive wheel comprises two parallel disposed ring discs spaced apart from each other, and

said driver crosses are rotatably mounted between said ring discs.

4. The drive, as set forth in claim 3, wherein each of said piston rod ends has running rollers rolling on the periphery of said discs.

5. The drive, as set forth in claim 4, wherein each of said driver crosses has a claw-like driver,

each of said drivers has on its backside a run-up out which projects slightly beyond the periphery of said discs and is transferred into the claw of the following of said drivers, if the following claw-like driver is in the ready position for engagement with said piston rod end.

6. The drive, as set forth in claim 5, which includes an arresting pawl elastically swingable in one direction, and

one of said arresting pawls is coordinated to each of said driver crosses for securing of said driver crosses in predetermined positions.

References Cited UNITED STATES PATENTS 8/1960 Graff et a1. 74-128 9/1963 Grumann 74-568 US. Cl. X.R. 

